This is a ballad by arguably the greatest dhadi (Sikh balladeer) in Sikh History.
Dhadis originated during the time of Guru Hargobind Sahib. These Balladeers would go from village to village recounting Sikh history and reminding Sikhs to remain steadfast in a time of great tyranny and oppression. The tradition continues unabated and will so continue until Khalsa Raj is established.
Giani Dya Singh Dilbar (the one with heart) was considered dangerous enough to have his passport revoked by the invader. As you listen to this Sikh ballad, you will realize why.